title: Impedimetric immunosensor based on gold nanoparticles modified graphene paper for label-free detection of Escherichia coli O157:H7.
abstract: In this study, a low-cost and robust impedimetric immunosensor based on gold nanoparticles modified free-standing graphene paper electrode for rapid and sensitive detection of Escherichia coli O157:H7 (E. coli O157:H7) was developed. Graphene paper was prepared by chemical reduction of graphene oxide paper obtained from vacuum filtration method. Scanning electron microscope, Raman spectroscopy and X-ray diffraction techniques were employed to investigate the surface morphology and crystal structure of the prepared graphene paper. The gold nanoparticles were grown on the surface of graphene paper electrode by one-step electrodeposition technique. The immobilization of anti-E. coli O157:H7 antibodies on paper electrode were performed via biotin-streptavidin system. Electrochemical impedance spectroscopy was used to detect E. coli O157:H7 captured on the paper electrode. Results show that the developed paper immunosensor possesses greatly enhanced sensing performance, such as wide linear range (1.5 × 10(2)-1.5 × 10(7) cfu mL(-1)), low detection limit (1.5 × 10(2) cfu mL(-1)), and excellent specificity. Furthermore, flexible test demonstrate the graphene paper based sensing device has high tolerability to mechanical stress. The strategy of structurally integrating metal nanomaterials, graphene paper, and biorecognition molecules would provide new insight into design of flexible immunosensors for routine sensing applications.
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Yixian
authors.initials: Y
authors.lastname: Wang
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Ping
authors.forename: Zunzhong
authors.initials: Z
authors.lastname: Ye
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Yibin
authors.initials: Y
authors.lastname: Ying
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D058266:Dielectric Spectroscopy / Q000379:methods; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000382:microbiology; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry*; D010209:Paper
chemical_list: D055910:Antibodies, Immobilized; D006046:Gold; D006108:Graphite
keywords: Gold nanoparticles; Graphene paper; Impedimetric immunosensor; Lab-free detection